I believe that the thing I like the most about this pairing is that these two bring out the best in each other. Raven was able to break through Damian's rough exterior and bring out a happier and more pleasant side that nobody else has been able to do so far. She had to put up with a lot of his crap but in the end Raven made Damian a better person. Plain and simple. Oh sure, he will still maintain some of his trademark Damian personality but no longer will he be the insufferable jerk that he once was. (Just look at how Damian was in the Judas Contract. He was much more sympathetic towards others. Particularly when he went to talk to Terra before she betrayed the team, he was willing to help her out and get through the rough patch she was going through).

Damian even gave up the chance to bring his Grandfather back because he refused to kill Raven. Raven knew how much Damian's grandfather meant to him after looking into his memories. So the fact that he was willing to give that all up just to save her goes to show how much he truly cares for her.

You, also can't forget how caring Raven was in this movie (justice league vs teen titans). She was willing to stay in hell and give up living a decent life of her own in order to watch over her father to keep everyone out of harms way because of how much she cares for her friends. And despite all that and the risk the world has by Raven not staying in hell to watch Trigon. Seeing Damian be the one to tell her that her home is with the titans after all that went down is somewhat touching and seeing Raven smile at the fact that she has a place to call home and seeing how her friends all truly care for her and would do anything for her is pretty touching.

Then in the Judas contract it was nice to see Raven give Damian Titus in order to comfort him and to give Damian something else to cling on to and take care of. It does a good job of showing the kind side that Raven has towards Damian and further strengthens the bond that these two have.